Erreur dns

Bonjour,
je n'arrive pas à me connecter sur de nombreux sites.
A chacune de mes requêtes, voici le message qui apparait:

DNS Error - Server cannot be found

Quelqu'un peut-il m'aider s'il vous plait?

Je vous envoie également un log hijackthis :

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 20:02:13, on 13/06/2008
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)
Boot mode: Normal

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Avira\AntiVir PersonalEdition Classic\sched.exe
C:\Program Files\Avira\AntiVir PersonalEdition Classic\avguard.exe
C:\Program Files\IVT Corporation\BlueSoleil\BTNtService.exe
C:\Program Files\COMODO\Firewall\cmdagent.exe
C:\Program Files\Fichiers communs\LightScribe\LSSrvc.exe
C:\WINDOWS\system32\HPZipm12.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Fichiers communs\Ulead Systems\DVD\ULCDRSvr.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Avira\AntiVir PersonalEdition Classic\avgnt.exe
C:\Program Files\COMODO\Firewall\cfp.exe
C:\WINDOWS\system32\ctfmon.exe
C:\WINDOWS\system32\wuauclt.exe
C:\Program Files\Internet Explorer\IEXPLORE.EXE
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://www.crawler.com/search/dispatcher.aspx?tp=aus&qkw=%s&tbid=60327
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.google.ci/?gws_rd=ssl
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = https://www.msn.com/fr-fr/?ocid=iehp
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,SearchAssistant = http://www.crawler.com/search/ie.aspx?tb_id=60327
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,CustomizeSearch = http://dnl.crawler.com/support/sa_customize.aspx?TbId=60327
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://www.crawler.com/search/ie.aspx?tb_id=60327
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch = http://dnl.crawler.com/support/sa_customize.aspx?TbId=60327
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: RealPlayer Download and Record Plugin for Internet Explorer - {3049C3E9-B461-4BC5-8870-4C09146192CA} - C:\Program Files\Real\RealPlayer\rpbrowserrecordplugin.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O2 - BHO: SearchSettings Class - {E312764E-7706-43F1-8DAB-FCDD2B1E416D} - C:\Program Files\Search Settings\kb127\SearchSettings.dll
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\Avira\AntiVir PersonalEdition Classic\avgnt.exe" /min
O4 - HKLM\..\Run: [COMODO Firewall Pro] "C:\Program Files\COMODO\Firewall\cfp.exe" -h
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O20 - AppInit_DLLs: C:\WINDOWS\system32\guard32.dll C:\PROGRA~1\Comodo\Css\cssdll32.dll
O23 - Service: Avira AntiVir Personal – Free Antivirus Scheduler (AntiVirScheduler) - Avira GmbH - C:\Program Files\Avira\AntiVir PersonalEdition Classic\sched.exe
O23 - Service: Avira AntiVir Personal – Free Antivirus Guard (AntiVirService) - Avira GmbH - C:\Program Files\Avira\AntiVir PersonalEdition Classic\avguard.exe
O23 - Service: BlueSoleil Hid Service - Unknown owner - C:\Program Files\IVT Corporation\BlueSoleil\BTNtService.exe
O23 - Service: COMODO Firewall Pro Helper Service (cmdAgent) - Unknown owner - C:\Program Files\COMODO\Firewall\cmdagent.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Fichiers communs\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: iPodService - Apple Computer, Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - C:\Program Files\Fichiers communs\LightScribe\LSSrvc.exe
O23 - Service: Pml Driver HPZ12 - HP - C:\WINDOWS\system32\HPZipm12.exe
O23 - Service: Ulead Burning Helper (UleadBurningHelper) - Ulead Systems, Inc. - C:\Program Files\Fichiers communs\Ulead Systems\DVD\ULCDRSvr.exe

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End of file - 4595 bytes

Configuration: Windows XP
Internet Explorer 6.0